Skeleton cord grip



March 8, I949. 5. J. JANKURA 2,463,542

SKELETON CORD GRIP Filed July 17, 1946 INVENTOR ATTORNEYS Patented Mar. 8, 1949 SKELETON CORD GRIP Steven J. Jankura, Bridgeport, Conn., assignor to Harvey Hubbell, Incorporated, Bridgeport, Conn., a corporation of Connecticut Application July 17, 1946, Serial No. 684,383

6 Claims. (Cl. 173-322) This invention relates to a cord grip for relieving the strain of the conducting cord upon the connections to contacts of electrical connectors, such as attachment plugs and the like.

In certain cord grips now commonly used, the clamping portion of the grip clamps the cord in a plane substantially normal or at right angles to the clamp supporting arms which are shaped around the connector body. Thus, when the clamps are tightened around the cord, the arms tend to crush the plastic connector body between them, causing undue breakage. Also, as in this arrangement the arms bend about spaced axes parallel to the planes of the clamps when drawn up, this action shifts the clamps out of parallelism so they tend to bind on the clamping screws and to grip the cord on one end more than on the other, and they therefore do not grip the cord uniformly across the width of the clamps.

One object of my device is to so construct the clamps with relation to the supporting arms that no undue strain is placed on the connector body when assembled.

Another object is to provide a. device in which the clamping grips remain substantially parallel and their grip on the cord is substantially uniform for the whole width of the clamps.

A further object of the device is to accomplish the above objects and still provide a simple and efficient cord grip which will relieve the strain on the wire connectors within the cord connector, and which will prevent fraying of the end of the cord.

With these and other objects in view I have devised the construction illustrated in the accompanying drawing forming a part of this specification. It is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In the drawing:

Fig. l is a top view of my device attached to a cord connector body;

Fig. 2 is a side view looking from the right of Fig. 1, showing a cord clamped by my device and with a section removed to show a detail;

Fig. 3 is a bottom view of the device attached to a cord connector body;

Fig. 4 is a top view of the device removed from the connector body;

Fig. 5 is a bottom view of the device removed from the connector body; and

Fig. 6 is a partial section taken substantially on line 6--6, Fig. 2.

For illustrative purposes I have shown my device in use with a three wire male cord connector or attachment plug cap comprising a connector or cap body In and three contact blades II attached to the body by means of molded inserts l2 passing through the base plates 9 and riveted or turned over in the usual manner, and each contact blade having a binding screw l3, as a means for connecting the conductor wires of cable or cord M to the contact blades II. It is to be understood, however, that my device is not limited to use solely with this connector or cap body illustrated, but may be used with any suitable cord connector, plug attachment, or the like.

The cord grip l5 constructed preferably of metal, or suitable plastic or other material, comprises a ring shaped member Hi, the inside diameter of which is of a size to fit snugly over the substantially circular lower portion H of the connector body In. The top of the ring I6 is turned over at substantially right angles to the ring I6 to form an annular flange |8 which butts against an annular ridge IS on the connector body ID, as at l9, Fig. 6. Projecting upwardly from the flange l8 at diametrically opposite points on the flange, so that they are located in a plane extending diametrically of the cap, are two arms or straps 20 and 2|, supporting the clamps or grips 22 and 23 which are formed upwardly at an angle substantially perpendicular to the straps 20 and 2| and at one side edge thereof, so that they face one another at a position immediately above the circular cord opening 24 in the connector body I. The faces of the clamps 22 and 23 are curved inwardly or concaved as at 25 and 26 to substantially fit the shape of the conductor wire cable or cord [4 clamped between them. As a means for tightening the clamps 22 and 23 around the cord [4, a pair of lugs 21' with holes 28 is provided on the clamp 22 to receive the screws 29, which screw into tapped holes 30 in the lugs 3| on the clamp 23. By tightening the screws 29 the clamps 22 and 23 move toward each other on a plane substantially parallel to the straps 20 and 2| clamping the cord l4 between them. It is clear, however, that as the clamps 22 and 23 move parallel to the straps 20 and 2|, or in the general direction of the planes of these straps, the position of the straps is not changed with relation to the connector body l0 and thus there is no danger of the straps being forced against the body or crushing the connector body as the clamps 22 and 23 are tightened around the cord M. In other words, movement of the clamps shifts the arms or straps 20 and 2| edgewise, or in the planes of these straps, which is substantially normal to the diametrical plane in which the arms are located, so that they are not pressed against the body member I0. They therefore cannot apply any pressure to the body to crush or break it. This arrangement, therefore, overcomes the objection of the old type, where the straps are moved toward or against the body when the clamps are tightened, with the result that they apply pressure to the body which often crushes or breaks it. The upper edges of the curved portions 25 and 26 of the clamps 22 and 23 are rolled outwardly, as at 32 and 33, to prevent theedge'from biting into the oord- IA when it is secured between the clamps.

To wire the device, the clamps 22 and 23 are spread to receive the cord l4 between them. The

. also be seen thatmy device securely-clamps the cord l4 so as to relieve the strain on the connections of the lead wires to the contacts ll. As

the movements of theclamps 22 and 23shift'the strapsZlland 2| edgewise or in the planes of these :straps theymaintain the same relative positions with respectto the insulating body l instead of being shifted toward this body, as in the old forms of these devices, which old arrangements applypressure to the body and often crush or break it.

.Having thus setforth the nature of my invention, I claim:

,1.. In a device of'the character described an -electrical, connector comprising a body of insu- .J lating material provided .with. an annular shoul- ,,der spaced from its inner end and an openingfor va. conductor cord, electrical contacts to which the conductors of the cord may be connected, a. cord ,grip comprising a ring embracing the body and .seated against said shoulder, substantially flat arms secured to the ring and extending inwardly therefrom over the body from opposite sides,

each arm beingprovided with a clamp togrip the cord withthe clamps extending in opposite directions from. therespective arms in a plane substantially parallel ,to the diametrical plane in .whlchthe two arms are located, ears on each vclamp, and screws through the. ears for drawing theclampsagainst the opposite sides of a conductor cord. in said opening. and arranged to shift .the clampsinadirection edgeways of thearms .so thatthese arms move edgeways andina direction substantiallynormaltothe diametricalplane of the arms.

.2. In combination,.anelectrical connector including -.a .body member I of insulating material provided with .an annular shoulder spaced from .one=en d, electrical contactamounted in .thebody, said body being provided with anopening :for passage of ,a. conductor leading .to said contacts, a .-cord -;grip.comprising a ring embracing .the .body vand q seated against said shoulder, a ,pair of ,arms of .greater .widththan thickness securedto -.the ring. at. opposite .sidesofthe body and curved ,inwardly over the. body toward each other, in substantially-a diametrical plane through the axis .of the body eachlarm terminating in a con- ;caved clampto grip'the cord and with the clamps extending in opposite directions .from .their .rev.spective arms in apIane-substantially parallel .to .saiddiametrical plane, opposed ears .on .the clampsand. screws through the. ears for clamp- .ingthe-clamps on opposite sides'of a conductor cord and ina directionedgeways of the arms.

,3. A separable electric fitting comprising a plug member of insulating, material provided with .a-nl openingfona conductor cord leading to con- ,tacts mounted in said memberyastrain relief fit- ..tingqcomprising .a ring embracing the member.

a pair of arms extending inwardly over the outer -portion'of the-member toward the opening from 'the ringatopposite sides of the'member, a concaved clamp connected to each arm at one end .of the clamp only, said clamps extending in opposite directions from the respective arms opposed to each other on opposite sides of the opening and in planes substantially parallel to the plane in which the arms are located, and clamping-screws connecting the clamps to clamp them on opposite sides of a cord in said opening and arranged to move the clamps in a direction subsides of the body and extending outwardly and inwardly overthe outer portion of the body toward said opening, a concaved clamp on each arm, said clamps being opposed to each other on opposite sides of the opening and extending in oppositedirections from their respective arms in planes substantiallyparallel to the plane in which the arms are located, and clamping screws'connecting the clampsto clamp them on opposite sides of a cord in the opening and arranged to "move the clamps in a direction edgewise of the arms.

5. A skeleton cord grip of the character described comprising a ring adapted to embrace the insulating body of a separable contact fit- -ting,-a pair of armscurved laterally and inwardly toward each ,otherfrom diametrically opposite sides of the ring, a concaved clamp for a conductor cordon the free end of each arm, said clamps being opposedtoeach other and arranged in planes substantially parallel to the plane in which the arms are located and extending in opposite directions from their respective arms in'the general direction in which the arms-are curved, and screws connecting the clamps to clamp them on oppositesides of a conductor cord and arranged to shift the clamps in a directiontransverse'to'theplane in which the arms arelocated.

-6. 'A skeleton cord grip'of-the character described comprising a'ring-adapted'to embrace the insulating body of a separable contact'fitting, a 'pair of substantially 'flat arms extending from opposite sides of 'the ring and curved'laterally and inwardly toward eachother, said arms each terminatin in a concaved-grip connected atone end to itsarm and extending in thesame direction the arm is curved,-said grips being opposedtoeachother and arranged in planes substantially parallel to the plane in which the arms are located, and screws connecting the clamps to clamp them on opposite sides of a conductor cord and arranged to shift the clamps in a direction edgewise of-said arms.

STEVEN 'J. 'JANKURA.

REFERENCES CITED The following references are of .record in the file of this-patent:

UNITED STATES PATENTS Number Name .lJate 1,951,312 Nero Mar. 13, .1912 2,186,751 .Chirelstein. Jan.'9,'1940 

